Survival ofCorynebacterium sepedonicum at freezing and at wide fluctuations between freezing and above-freezing temperatures
The survival ofCorynebacterium sepedonicum, the bacterial ring rot pathogen of potatoes, on burlap surfaces held at constant freezing and above-freezing temperatures and under wide fluctuations of these temperatures was investigated by root-inoculating potato stem cuttings with aqueous suspensions prepared from these surfaces. The pathogen survived and remained infectious on burlap for 53 mo at all constant freezing temperatures, and its infectivity did not diminish throughout this period at either −20 or −40°C. At 42 months, viable ring rot bacteria were no longer detected at a constant temperature of 5°C.
In a second experiment, ring rot bacteria survived and remained infectious on burlap for 23 months at fluctuating temperatures of −40 to 5°C and −40 to 25°C, but only survived for 12 months at 25°C. However, results of this study indicate that wide fluctuations between freezing and above-freezing temperatures caused decreased infectivity of the pathogen.
Additional Key WordsSurvival ring rot bacteria freezing and fluctuating temperatures
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